如何构建含本地Go包的Docker镜像？解决导入路径未含主机名错误

Let's break down what's causing this error and fix it step by step:

Root Cause #

The error package docker_test/mult: unrecognized import path "docker_test/mult" pops up because your Go code's import path doesn't align with the directory structure inside the Docker container's GOPATH.

In the golang:1.9.1 image, the default GOPATH is /go, so Go expects packages to live under /go/src/[import-path]. Your Dockerfile copies the mult package to /go/src/app, but your main.go is trying to import it as docker_test/mult—a path that doesn't exist in the container's GOPATH.

Step 1: Fix the Import in main.go #

Open your main.go file and update the import line from:

import "docker_test/mult"

To:

import "app"

This matches the exact path where you're placing the mult package inside the container (/go/src/app).

Step 2: Correct the Dockerfile #

Your Dockerfile has a critical path mistake in the WORKDIR directive, plus we'll confirm the copy logic is solid. Here's the revised version:

FROM golang:1.9.1
# Copy the mult package to the proper GOPATH location
COPY ./docker_test/mult /go/src/app
# Set working directory to the app package path (full absolute path required!)
WORKDIR /go/src/app
# Copy main.go into the working directory
COPY ./docker_test/main.go .
# Download external dependencies (safe to keep even for local packages)
RUN go get -d -v ./...
# Compile and install the app binary
RUN go install -v ./...
# Define runtime command and entrypoint
CMD ["app"]
ENTRYPOINT ["app", "-f=7", "-s=9"]

Key Fixes: #

• WORKDIR Path: Changed WORKDIR go/src/app to WORKDIR /go/src/app—without the leading /, Docker would create the directory relative to the base image's root, leading to an invalid GOPATH structure.
• Import Alignment: The copy logic ensures the mult package lives at /go/src/app, so the updated import path app in main.go works as expected.

Step 3: Verify Local Directory Structure #

Double-check your local project structure matches what the Dockerfile expects. From your /gowork/src directory, it should look like this:

/gowork/src/
├── Dockerfile
└── docker_test/
    ├── main.go
    └── mult/
        └── [your mult package files, e.g., mult.go]

Now run docker build -t test_1 . again—it should build successfully!

内容的提问来源于stack exchange，提问作者Mzia